Various cryptosystems, such as elliptic curve and pairing-based cryptosystems, in resource-constrained security applications rely on finite field multiplication. For applications such as these, a digit-serial multiplier has the potential features to achieve a trade-off between space and time complexities. The authors propose an efficient decomposition of the multiplication into four independent sub-multiplication units to facilitate parallel processing, which is additionally facilitated by the systolic structures of the sub-multiplication units. The proposed architecture uses a four-bit scheme to construct a novel processing element, instead of using only one bit as is currently used in similar multipliers. The results of the synthesis show that the proposed digit-serial dual basis multiplier eliminates up to 96% of the critical path delay.

Fault injection attacks have constituted a serious threat against cryptographic integrated circuits (ICs). However, the security test nowadays is just sample test with workload statistics and experiences as the qualitative criterion, and results in costly, time-consuming and error-prone test procedures. This study presents a design for security test (DFST) method for cryptographic ICs against fault injection attacks. The DFST involves identifying the sensitive registers for various crypto modules, inserting the scan chains and generating the specific test patterns for security test. Then the security test is conducted on the manufactured cryptographic ICs with the industrial automatic test equipment. With this DFST method, a fast and automatic security test can be applied onto volume production of cryptographic ICs. Experimental results on an RSA implementation demonstrate the validity of this method.

Shilling attacks have been a significant vulnerability to collaborative filtering based recommender systems recently. There are various studies focusing on detecting shilling attack users and developing robust recommendation algorithms against shilling attacks. Although many studies have been devoted in this area, few of them use soft co-clustering and consider both labelled and unlabelled user profiles. In this work, the authors explore the benefits of combining soft co-clustering algorithm with user propensity similarity method and present a soft co-clustering with propensity similarity model or CCPS for short, to detect shilling attacks. Then they perform experiments using MovieLens dataset and Jester dataset to analyse it with respect to shilling attack detection to demonstrate the effectiveness of CCPS model in detecting traditional and hybrid shilling attacks and enhance the robustness of recommender systems.

In multi-secret sharing (MSS) scheme, a dealer distributes multiple secrets among a set of participants, each of them according to an access structure. In this study, the authors propose a novel linear MSS with computational verifiability that provide many functions for practical applications in comparison with the previous works focusing on MSS schemes in the general scenario. This scheme has the same advantages as previous schemes; moreover, it is verifiable and multi-use secret sharing. Furthermore, in this scheme the secret reconstruction is according to the dealer's preassigned order. Also, they prove the security of the authors’ scheme in the standard model.

In this study, the author formally proves that designing attribute-based encryption schemes cannot be easier than designing identity-based encryption schemes. In more detail, they show how an attribute-based encryption scheme which admits, at least, and policies can be combined with a collision-resistant hash function to obtain an identity-based encryption scheme. Even if this result may seem natural, not surprising at all, it has not been explicitly written anywhere, as far as they know. Furthermore, it may be an unknown result for some people: Odelu et al. in 2016 and 2017 have proposed both an attribute-based encryption scheme in the discrete logarithm setting, without bilinear pairings, and an attribute-based encryption scheme in the RSA setting, both admitting and policies. If these schemes were secure, then by using the implication proved in this study, one would obtain secure identity-based encryption schemes in both the RSA and the discrete logarithm settings, without bilinear pairings, which would be a breakthrough in the area. Unfortunately, the author presents here complete attacks of the two schemes proposed by Odelu et al.

Wireless sensor networks (WSNs) have been deployed in various commercial, scientific, and military applications for surveillance and critical data collection. A serious threat to sensor nodes is malicious code injection attack that results in fake data delivery or private data disclosure. Memory attestation used for verifying the integrity of a device's firmware is a promising solution for detecting an infected sensor node; particularly, low-cost software-based schemes are suitable for protecting resource-constrained sensor nodes. However, a software-based attestation usually requires some additional mechanisms for providing reliable integrity evidence when the sensor nodes communicate with the verifier through a multihop setting. Alternative hardware-based attestation (e.g. trusted platform module) ensures a reliable integrity measurement that, however, is impractical for certain WSN applications primarily because of the high computational overhead and high hardware cost. The authors propose a lightweight hardware-based memory attestation scheme against the malicious code injection attack, and the proposed scheme employs a lightweight tamper-resistant hardware security module, which is free from any complicated cryptographic computation and is particularly suitable for low-cost sensor nodes. In addition, experimental results demonstrating the effectiveness of the proposed scheme are presented.

Software defined networking (SDN) enables the network more flexible, open and programmable. However, as the network control and intelligence lay on the centralised controller, its security becomes even more important, and a minor change may have a direct crucial impact on the entire network. Numerous research results have shown that the SDN controller not only faces traditional security threats, but also has to tackle the challenges introduced by its unique centralised architecture. In this study, the authors present a novel SDN controller framework called mimic network operating system (MNOS). The main ideas behind MNOS are cyberspace mimic defence (CMD), which is proposed by academician Wu's team recently. By introducing the CMD into the design of SDN controllers, they come out with an N -variant controller framework with dynamic, heterogeneous and redundant characteristics. MNOS has a design-in security mechanism, its main features are: (i) effectively protects the controller from the attacks as hijacking and data modification without relying on prior knowledge of vulnerabilities; (ii) constantly monitors the behaviours of variants to detect unknown attacks; (iii) greatly improves the reliability of controllers. Theoretical analysis and experimental results show that MNOS can achieve considerable security gains and effectively improve security performance of SDN controller.

This study presents an implementation flaw in Differential Power Analysis Contest (DPA) Contest v4. This version of DPA Contest uses Advanced Encryption Standard (AES) protected against side-channel attacks using rotating s-box masking (RSM) countermeasure. The authors identify a flaw in the masking scheme that was used in this contest. More specifically, the problem lies in an unfortunate choice of values for masks. An unbalance in the masking scheme leads to a first order leakage. This vulnerability could be used in order to mount a first order side-channel attack against AES-RSM. The attack was implemented and tested on DPA Contest v4 reference traces. The authors also provide a way to avoid the newly discovered problem and suggest new values for masks.

The well-known stream cipher Grain v1 is one of the finalists of European eSTREAM project. In this study, a novel guess-and-determine attack on Grain v1 is introduced. The attack primarily employs a new conditional BSW sampling technique and the main creative idea is that the conditions are set not only on state bits but also on the updates of the registers for the BSW sampling technique. It is shown that using this technique we can further reduce the sampling resistance of Grain v1 to which is the best result so far. The attack leads to an efficient internal state recovery of Grain v1 with only online time employing a memory of , requiring keystreams each of length and preprocessing time. It is shown that these figures are obviously better compared with the previous results. This is also the first attempt to control the updates of the registers of Grain v1 in the guess-and-determine attack and hopefully this provides new insights for cryptanalysis on such compact stream ciphers.

Time synchronisation is a fundamental requirement for the IEEE802.15.4e-based industrial Internet of Things, allowing it to reach low-power and high-reliability wireless network through time synchronisation. If malicious adversaries launch time synchronisation attacks to IEEE802.15.4e-based networks, the entire network communication will be paralysed. In this study, the authors introduce two types of time synchronisation attacks: (i) absolute slot number (ASN) and (ii) timeslot template attack. In ASN attack, the new nodes may receive an incorrect ASN value, which prevents synchronisation with the typical network, while in the timeslot template attack, the malicious node can make the legitimate nodes calculate the error clock offset. The authors propose an enhanced secure time synchronisation protocol to defend against these attacks, which include Sec_ASN and TOF algorithm. The Sec_ASN and threshold filter (TOF) algorithms are used to defend against ASN attack and timeslot template attacks, respectively. Finally, the authors run a thorough set of simulations to assess the effectiveness of the proposed attacks as well as the proposed countermeasure. The results show that the attacks can significantly destroy the time synchronisation protocol, but can be successfully defended using the proposed mechanisms.

SKINNY is a family of lightweight block ciphers proposed at CRYPTO 2016, which follows the TWEAKEY framework and takes a tweakey input. It is shown that SKINNY family not only has good hardware/software performances, but also provides strong security guarantees against differential/linear cryptanalysis. In this study, the authors study the security of SKINNY against the impossible differential attack. First, they get some properties of the subkeys of SKINNY by analysing its key schedule. Then, combining with the early-abort technique and the greedy strategy, they present impossible differential attacks on SKINNY based on an 11-round impossible differential. Let SKINNY-n-k be the SKINNY cipher with n-bit block size and k-bit tweakey size. On the basis of their method, 17-round SKINNY-64-64 (resp. SKINNY-128-128) can be broken in (resp. ) 17-round encryptions, 19-round SKINNY-64-128 (resp. SKINNY-128-256) can be broken in (resp. ) 19-round encryptions and 21-round SKINNY-64-192 (resp. SKINNY-128-384) can be broken in (resp. ) 21-round encryptions. To the best of their knowledge, these results are currently the best results with respect to the attacked rounds.

The theft of personal information to fake the identity of a person is a common threat normally performed by individual criminals, terrorists, or crime rings to commit fraud or other felonies. Recently, the Spanish identity card, which provides enough information to hire online products such as mortgages or loans, was updated to incorporate a near-field communication chip as electronic passports do. This contactless interface brings a new attack vector for criminals, who might take advantage of the radio-frequency identification communication to virtually steal personal information. In this study, the authors consider as case study the recently deployed contactless Spanish identity card assessing its security against identity theft. In particular, they evaluated the security of one of the contactless access protocol as implemented in the contactless Spanish identity card, and found that no defences against online brute-force attacks were incorporated. They then suggest two countermeasures to protect against these attacks. Furthermore, they also analysed the pseudo-random number generator within the card, which passed all the performed tests with good results.